1. Field of the Invention
The present invention pertains to truck bodies and tops generally, and more specifically to removable brackets in combination with removable boards or sidewall extensions. The brackets and boards extend the side wall vertical height of a cargo area, such as a truck body dump box or cargo box.
2. Description of the Related Art
Dump trucks, flat-bed trucks, pick-up trucks, trailers and various other cargo carrying vehicles have been designed, often with dimensions and features fairly specific to a particular cargo. These vehicles are quite expensive, but are limited to transporting one specific cargo. As a result, the cost of the vehicle is only recoverable through the transport of that one specific cargo. In many situations, these vehicles could have application for many more diverse types of cargo, but are limited by inadequate or completely missing sidewalls.
For example, a dump truck dumping bucket might typically be designed for an optimum load when hauling sand or gravel. The dump box for that load needs only be sufficiently deep to retain a full load of sand. Owing to the weight of sand, a relatively shallow box will typically suffice. Lower sides simplify the filling process, particularly when a skid steered machine or front-end loader is used to fill the dump truck. The back will often be gently sloped, to allow ready discharge of the sand. This type of box will be optimum for sand and gravel, but will not be able to carry bulkier and less dense materials, such as loose vegetative or plant matter, owing to the limited height of the side walls of the box.
However, the same dump truck could be used to transport less dense materials, such as various grains or plant matter, if the dump box were sufficiently enclosed to retain the plant matter. Several artisans have disclosed techniques for retrofitting an existing vehicle, to expand the cargo that may be transported. Ward et al in U.S. Pat. No. 5,752,734, incorporated herein by reference, illustrate a set of side and back rails or walls, extending above a pick-up truck box, made from special slotted brackets. Wooden rails or plywood panels are inserted into the bracket slots, thereby forming a special purpose rack. While the Ward et al invention does expand the utility of an existing pick-up box, the rails are restrictive, limiting the sizes and types of lumber that may be used. Furthermore, the racks are relatively large and expensive to produce, and have little utility where a relatively dense load is to be carried, owing to their disproportionate height.
Sanders, in U.S. Pat. No. 5,772,271 incorporated herein by reference, illustrates a dump truck body including small tracks that support solid and see-through panel sections. Nevertheless, the Sanders invention, like the Ward et al invention, is limited by special tracks that necessitate a particular thickness insert. Furthermore, the Sanders invention is designed to be built into the truck body at the time of manufacture, and so cannot be retrofit onto existing special purpose vehicles already on the road. Similar extensions are illustrated in U.S. Pat. No. 4,826,237 to Socha, incorporated herein by reference. Krause in U.S. Pat. No. 5,056,752, also incorporated herein by reference, illustrates a flat bed trailer, with four corner brackets that can be positioned for a particular load, to provide bracing at the base of the load. However, this limited bracing provides little expansion in the type of cargo that may be carried, and instead merely simplifies the process of anchoring the load onto the trailer.
Other trailer and vehicle bodies are known in the art that provide no way to attach any sort of side board. Exemplary of this type of trailer is a hydraulic dumping trailer with sloping side walls. The top rails are smooth and void of attachment points or anchors.
What is needed then, and which is absent from the prior art, is a way to simply and cost-effectively retrofit an existing cargo vehicle to expand the type of cargo that may be transported by the vehicle.